At present, the rocket is the only vehicle that can make an object reach the speed of the universe, overcome or get rid of the gravity of the earth and enter space. The speed of the rocket is obtained by the operation of the rocket engine. As early as 1903, tsiolkovsky derived the ideal velocity formula V=ωLnMo/Mk for a single-stage rocket, which is called the Tsiolkovsky formula. ω is the injection speed of the engine, Mo and MK. They are the initial mass of the rocket and the mass when the engine is turned off (the propellant is used up). Mo/Mk is called the mass ratio of the rocket.
According to this formula, the rocket speed is directly proportional to the jet speed of the engine and increases with the increase of the rocket mass ratio. Even with the best liquid hydrogen and liquid oxygen propellants, the injection speed of the engine can only reach 4.3 ~ 4.4 km/s, so it is impossible for a single-stage rocket to send an object into space orbit, and a multi-stage rocket must be used to send a spacecraft into space orbit through relay.
Rockets used to carry spacecraft are called space launch vehicles, and military bombs are called rocket weapons (uncontrolled) or missiles (controlled). Space launch vehicles are generally composed of power system, control system and structural system, and some are equipped with additional systems such as telemetry and safe self-destruction.
There are several connection modes between stages of multistage rockets, including series connection, parallel connection and series-parallel connection. Series connection refers to connecting several single-stage rockets in series into a straight line; Parallel connection means putting a large single-stage rocket in the middle, called the core stage, and bundling several smaller rockets around it, generally called booster rocket or booster, that is, booster stage; The core stage of series-parallel multistage rocket is also a multistage rocket.
The connection and separation between stages of multi-stage rocket, between rocket and payload and fairing are realized by connecting a separation mechanism (often referred to as separation mechanism). The separation mechanism is composed of an explosive bolt (or explosive cable) and an ejection device (or small rocket). Usually connected into a whole by explosive bolts or explosive cables; When separating, the explosive bolt or explosive cable explodes to unlock the connection, and then the two parts are separated by the ejection device or small rocket, or the powerful jet after the previous rocket engine is started.
Rocket technology is a very complex comprehensive technology, which mainly includes rocket propulsion technology, overall design technology, rocket structure technology, control and guidance technology, plan management technology, reliability and quality control technology, test technology and so on. On the missile side, there are warhead technologies such as warhead guidance and control, penetration, reentry heat protection, nuclear reinforcement and miniaturization.
Edit the historical origin of this paragraph.
According to ancient records, the word "rocket" first appeared in the Three Kingdoms period in the 3rd century A.D., with a history of 1700 years. At that time, in the battle between the enemy and ourselves, people called the arrow with flammable materials on its head an arrow, which was ignited and fired at the enemy, called a rocket. This is a weapon for fire attack. In essence, it is just an arrow with "fire", which is far from what we call a rocket now. After the invention of gunpowder in the Tang Dynasty, in the Song Dynasty, people tied a barrel full of gunpowder to an arrow shaft, or put gunpowder in the arrow shaft, lit the fuse, and then fired it. The arrow flies farther with the reaction force to the backward fire generated by the burning of gunpowder in flight. People call this kind of jet rocket a rocket. This kind of arrow, which spits fire backwards and is boosted by reaction force, has the embryonic form of a modern rocket and can be called the original solid rocket.
Rocket is a kind of jet propulsion device, which uses hot air to jet backward at high speed and uses the generated reaction force to push forward. Usually the word rocket also includes missiles, spaceships and even fireworks.
The most common rockets burn solid or liquid chemical propellants. Propellant combustion produces hot gas, which is sprayed to the tail of the rocket through the nozzle. Rockets bring their own fuel and oxidant, while other jet engines only need to carry fuel, and the oxygen needed for fuel combustion is taken from air. Therefore, rockets can be used outside the earth's atmosphere, while other jet engines cannot. When the rocket is launched, it generates huge thrust, which makes the rocket rise into the sky quickly in a short time. With the continuous reduction of fuel, the mass of the rocket itself is gradually reduced. As the distance from the earth increases, the influence of mass and gravity decreases, and the rocket speed becomes faster and faster.
When Saturn V rocket set off for the moon, five engines consumed nearly 3 tons of kerosene per second, and the thrust they generated was equivalent to the takeoff thrust of 32 Boeing 747s. It is impossible to determine the exact time when the rocket was invented. Most experts believe that China people developed practical military rockets as early as13rd century. /kloc-there were several technological advances in the 0/9th century: the paper shell of fuel container was changed to metal shell, which prolonged the duration of combustion; Formulation standardization of gunpowder propellant: creating a launch pad; Discovered the principle of spin orientation and so on. At the end of 19, rockets began to be used for non-military purposes, such as transporting lifeline to ships in distress at sea. 19 At the end of the 20th century, American scientist Goddard and several other experts laid the foundation of modern rocket technology and launched the first liquid fuel rocket.
In 1970s, the United States developed a brand-new rocket-powered spacecraft-the space shuttle. It is mainly divided into three parts: an orbiter with three main engines at the back of the fuselage; External fuel tank, filled with liquid hydrogen and liquid oxygen propellant (falling off after 5 minutes), to ensure the main engine to work; It is equipped with two separable solid fuel rocket engines (separated after 2 minutes), which are started at the same time as the main engine of the orbiter to provide thrust during the initial lift-off. 1981April 12, the first space shuttle "Columbia" was launched.
After China's ancient rocket technology was introduced to Europe, rockets were once classified as military equipment after improvement. Early rockets had short range and wide distribution of impact points, and were later replaced by artillery. After World War I, with the continuous progress of science and technology, rocket weapons developed rapidly and played a powerful role in World War II.
In 1980s, Swedish engineer Laval invented Laval nozzle, which improved the design of rocket engine. /kloc-at the end of 0/9 and the beginning of the 20th century, liquid rocket technology began to rise. 1903, к E tsiolkovsky of Russia put forward the idea and design principle of manufacturing large liquid rockets. 1March 926 16, American rocket expert and physicist R.H. Goddard flew the first uncontrolled liquid rocket. 1944, Germany used a controlled V-2 missile propelled by a liquid rocket engine for the first time in the war. 1931May, the IAF led by German scientist Herman Aubert successfully tested the first liquid rocket in Europe. By 1932, after visiting the liquid rocket launch test developed by the association, the German military realized the great potential of rocket weapons in future wars and began to organize a group of scientists and engineers to concentrate on secretly developing rocket weapons. By the early 1940s and the middle of World War II, Germany had successfully developed two kinds of missiles, V- 1 and V-2, which could be used in actual combat. Among them, V- 1 is a flying wing missile, which uses an air jet engine as the power device; V-2 is a ballistic missile powered by a rocket engine. After World War II, the Soviet Union and the United States successively developed various rocket weapons, including intercontinental ballistic missiles.
China has been developing new rockets since 1950s. 1970 On April 24th, the first artificial earth satellite was successfully launched by the Long March 1 three-stage carrier rocket. 1975165438+1On October 26th, the Long March II carrier rocket launched a recoverable heavy satellite with greater thrust. 1980 On May 18, a new rocket was successfully launched into the South Pacific. 1982, 10, the submarine successfully launched the rocket underwater. 1on April 8, 984, the geosynchronous test communication satellite was successfully launched by the Long March III carrier rocket with a three-stage liquid hydrogen and liquid oxygen rocket engine. 1On September 7th, 988, a meteorological satellite was successfully put into sun-synchronous orbit by cz-4. 1992 August 14, the newly developed Long March II E-type high-thrust carrier rocket launched the Australian Aarseth B 1 satellite into the predetermined orbit. All these indicate that China, as the birthplace of rockets, has entered the advanced ranks in the world in the field of modern rocket technology, and has steadily entered the international launch service market.
In the development of modern rocket technology, Qian Xuesen of China, Wernher wernher von braun of the United States and korolev tsiolkovsky of the Soviet Union all made outstanding contributions.
The hometown of the rocket is in China.
Although people have used balloons, airships and airplanes to fly in space, balloons and airships can only fly with the wind at low altitude.
Edit this regulation
According to international law, the nationality of the owner of the launch vehicle determines that the country must be responsible for any damage caused. Therefore, some countries require rocket manufacturers and launchers to abide by specific laws and regulations to compensate and protect people and property from possible influences.
Huang Chunping, a member of the Chinese People's Political Consultative Conference (CPPCC), head of the advisory group of manned space rocket system, and commander-in-chief of Shenzhou 5 rocket, said that the launch time of Shenzhou VII will be delayed by about half a year, and the planned launch in 2007 will be postponed to 2008. Different from "Shenzhou V" and "Shenzhou VI", the development of "Shenzhou VII" rocket focuses on spacesuit and valve braking. Because "Shenzhou VII" will realize spacewalk, whether astronauts can adapt to the sudden vacuum environment from cabin pressure, valve braking and spacesuit plays an important role.
Edit the introduction of this ship.
China will launch the Shenzhou VII manned spacecraft in 2008, when Chinese astronauts will make their first spacewalk. At present, the core technical difficulties such as air lock have been overcome, and the whole ship has entered the comprehensive testing stage. The Long March II F rocket used to launch the Shenzhou VII spacecraft is expected to be fully assembled before the end of 2007 12. It is reported that the "Shenzhou VII" spacewalk has higher assessment requirements for astronauts. Because the pressure in the spacesuit is lower than normal, it may release nitrogen in human tissues and form air embolism in blood vessels, leading to decompression sickness and even endangering people's lives. Therefore, after the astronauts put on the spacesuit, they must fully absorb the oxygen in the airlock, assist the working astronauts to return to the inner cabin (i.e. the orbital module), close the inner door, and then the airlock begins to decompress to vacuum, which is consistent with the vacuum state outside the spacecraft. At this time, the astronauts can leave the cabin. When returning to the cabin after completing the mission of leaving the cabin, it is necessary to decompress the spacesuit to a certain extent, and then inflate the airlock.
"Astronaut extravehicular activity is a difficult and high-risk activity." According to experts, the spacewalk of Shenzhou VII requires astronauts to do full experiments and training on the ground, and the ground training is generally carried out in a neutral pool with certain requirements for specific gravity. This kind of pool is usually built in a large test room. There is a spaceship in the pool, which uses the buoyancy of water to simulate the weightlessness in space. Then the astronauts trained in the pool for entry and exit operations.
Zhang, deputy commander of China's manned spaceflight project, said that the future Shenzhou VII spacecraft will not be a simple repetition of Shenzhou VI, and it has broken through many key technologies. Shenzhou VII spacecraft is still launched by Long March II F carrier rocket, which has successfully sent six shenzhou spaceship into space and has a mature technical foundation. At present, the procurement and production of parts for new launch vehicles have begun. Jing Muchun, the chief designer of the rocket, said that this time they will use higher quality components. In view of the previous flight situation of the rocket, researchers will also make partial improvements to this rocket to further improve its reliability. In addition, they are also considering adding some cameras to the rocket.
Starting from Shenzhou VII, China entered the second stage of manned space flight. At this stage, the scientific goals of astronauts' extravehicular walking and space rendezvous and docking will be realized one after another. All the launching tasks of the second phase project are undertaken by Chang-2 F rocket.
Spacecraft launch report
In order to let more people know about the launch comprehensively and comprehensively through the Internet, the Tian Fei hotline website will follow up the whole flight of Shenzhou VII, so that more people can know about Tian Fei and Jiuquan, the hometown of Tian Fei.
Edit the details of this paragraph.
Astronauts fly Shenzhou VII like airplanes.
Zhang Bainan, chief designer of China manned spacecraft system, told the reporter that two astronauts of Shenzhou VI conducted four "on-orbit interference force" experiments on June 5438+03, including opening and closing doors, putting on pressure suits, passing through the cabin and extracting condensed water. The results show that the astronauts' large-scale actions have little effect on the spacecraft attitude, and the spacecraft attitude remains good. Astronaut Fei Longjun, who was flying in space, learned the result and made four consecutive forward rolls on the spaceship the next day. Zhang Bainan said that this is the astronaut's own game, not arranged in advance. The results of this space flight show that Fei Longjun and Nie Haisheng can give orders correctly at any time from the moment they just took off to the moment they are ready to return, and they can control all kinds of equipment accurately, and the operations of opening and closing doors can also be successful at one time. Zhang Bainan said that with the foundation of this experiment, "Shenzhou VII" will arrange for astronauts to "fly a spaceship like an airplane"!
"Shenzhou VII" astronauts are going to take a spacewalk.
Academician Qi Faren believes that human beings go to heaven not for tourism, but for the research, development and utilization of space environment. In the past, Yang Liwei was just the first step to give it a try. It will take many people and many days to finish this task. For example, to assemble a space station or repair a satellite, people must get out of the cabin, and it takes at least two people to get out of the cabin. In the future, I will go to the space station by means of transportation, dock with the space station, and pick up the people inside after opening the door. From abroad, they spent a lot of experiments to do this. Now, according to our plan, "Shenzhou VII" hopes that people can get out of the cabin, which is called spacewalk by ordinary people. "Out of the cabin, of course. How far is it from the cabin? It can also be closer or farther. " Academician Qi Faren told reporters that the next step is to solve the rendezvous and docking in China, and there must be at least three people in the rendezvous and docking. Therefore, our spacecraft should have this ability: three people stay in the sky for seven days, and they can get 300 kilograms when they go up, and they can get 100 kilograms when they come back. If we succeed this time, we don't need two people to try for a few more days. Then we will leave the cabin next time. Academician Qi Faren believes that Shenzhou VII, who is about to leave the capsule, must solve two major problems on the basis of Shenzhou VI. Now astronauts have a sealed cabin in which they wear spacesuits. Without this cabin, there would be no air, so the spacesuit itself must be able to supply oxygen. The second is that when there is no temperature control, the spacesuit can guarantee its normal temperature, so this spacesuit is equivalent to a small sealed cabin, which is quite complicated. A more advanced spacesuit can also be equipped with an engine and leave a little fire, which is equivalent to a small spaceship. These conditions are needed to leave the cabin. Academician Qi Faren said that in the future, we should have airlock cabins on board. People should put on spacesuits and go in, close the door and open the outside door. If you open the door, the air will be exhausted, so there is an airlock. "I'm just talking about two main things. As astronauts, we have extravehicular spacesuits. As a spaceship, we must have an airlock cabin to ensure that there is an atmospheric pressure in the original cabin. "
Shenzhou VII can carry at least three astronauts.
Huang Chunping, head of the expert advisory group of the "Shenzhou VI" rocket system, said that by Shenzhou VII, the capacity of the spacecraft will increase accordingly, and there will be three astronauts at the meeting. According to the change of mission, the weight of spacecraft products is getting bigger and bigger, so the thrust required by rocket products is also increasing accordingly. The payload of the Shenzhou VI launch spacecraft is more than 8 tons, and it will be expanded in the future. A new large-scale rocket scheme for carrying Shenzhou VII has been worked out and is waiting for national approval. At present, some products have come out and there are prototypes. But a lot of ground tests are still needed. Since 1999, Huang Chunping has been the commander-in-chief of the rocket system from Shenzhou-1 to Shenzhou 5.
"Shenzhou VII" spacecraft needs elaborate decoration.
Academician Qi Faren of China Academy of Engineering told the reporter: "Let me give you an example, just like we have a rough house. If we buy a house and a rough house, whether you live together for three generations or a young couple, we will redecorate according to your requirements. Blank houses are all the same, and the basic appearance will never change. The propulsion module, the return module and the orbital module will not change, but from the beginning, Yang Liwei was alone, with no toilet and no kitchen. There is a kitchen and a toilet. When there are three people, such as when we are going to rendezvous and dock, we will leave the cabin in the future. Basically, the configuration will not change, the interior decoration will change, and it is finely decorated. "
Who will fly with Shenzhou VII?
Professor Yu, a researcher at the Air Force Institute of Aviation Medicine and a famous vestibular physiologist, said in an interview with this newspaper that it is not good for astronauts to be too old or too young. 38 years old is the best physiological age for flying, and it begins to decline from 43 to 45 years old. So, who is most likely to become the fourth astronaut in China? If "Shenzhou VII" is an unmanned spaceship, as experts say, does this mean that Liu Boming, Jing Haipeng, Zhai Zhigang and Wu Jie may not be able to fly because of their age? /kloc-will other members of the 0/4-person space brigade kill such a "dark horse" as Fei? If someone drives and three people drive, what kind of combination are Yang Liwei, Fei, Nie Haisheng, Liu Boming, Jing Haipeng, Zhai Zhigang and Wu Jie? The first batch of astronauts in China and a major general of the Air Force told this reporter that the new batch of astronauts in China have not yet entered the training stage. So, does this mean that the astronauts of Shenzhou VII or Shenzhou VIII are still 14 astronauts? In this regard, Wu Jie, an active astronaut, said before the launch of Shenzhou VI that his partner Zhai Zhigang had many advantages. At least he passed the test of Shenzhou 5, and he is a very good astronaut, very good in his astronaut brigade. Second, his reaction is very fast, he deals with special situations in training, and his judgment and decision-making are very accurate. Third, he is diligent. According to the training, someone else's information manual is at least this thick. When dealing with emergency special situations, he can train without reading the manual. He trained himself to be fully prepared. Then there is his cheerful personality and high popularity. Everywhere he went, there was laughter. Wu Jie also said that even if Shenzhou VI didn't succeed this time, Shenzhou VI became a starting point. As long as you are in this team, you will definitely fight for the dream of flying in round space. Zhai Zhigang also said: "It's not just Shenzhou VI. If Shenzhou VII has passed, it will continue to work hard and will continue to work hard."
Will there be female astronauts on Shenzhou VII?
Will the future "Shenzhou VII" have the first female astronauts? Professor Pang Zhihao, a researcher at China Academy of Space Technology, deputy editor of International Space magazine and China Institute of Aerospace Medical Engineering, told People's Daily Online that it will take three to five years for China to select female astronauts from next year. He predicted that Shenzhou VII would be launched in two years, and the first spacewalk test might be conducted. This means that "Shenzhou VII" can't have a female astronaut in the sky.
Edit this space experiment
The Chinese Academy of Sciences made public the contents of manned space experiments.
The person in charge of the Chinese Academy of Sciences said that the main task of the manned spacecraft engineering application system is to carry out space-to-earth observation, space science and technology experiments. The goal of China's manned space engineering application system (Phase I) is to vigorously promote and develop China's space science and space application technology, make valuable contributions to national economic construction and social development, and lay a foundation for future participatory space science and technology experiments.
Among them, the "Earth Observation Mission" aims at developing advanced space remote sensors and exploring the scientific research of the earth system, and determines on-orbit experiments and application tasks such as medium resolution imaging spectrometer, multi-mode microwave remote sensor (including microwave altimeter, radiometer and scatterometer), earth environment monitoring and remote sensing application research. Earth environmental monitoring includes solar constant monitoring, solar and earth ultraviolet radiation monitoring and earth radiation budget detection. The application research of remote sensing lays the foundation for the development of remote sensing application technology in China; Carry out research and demonstration on the application of imaging spectrum technology and microwave remote sensing technology in ocean, land and atmosphere.
"Space Science Research" has arranged space life science, microgravity science (including space material science engineering and microgravity fluid physics research engineering), space astronomy engineering, space environment prediction and monitoring tasks, with the goal of comprehensively improving the level of space science in China. "Space Life Science and Biotechnology" has developed a variety of space experimental equipment, and carried out research on space biological effect, space protein crystallization, space cell culture, space cell electrofusion, space protein and separation and purification of biological macromolecules. "Space Materials Science Research" develops multi-station crystal growth furnaces and crystal growth observation devices, conducts research and space growth of binary and ternary semiconductor photoelectric materials, transparent oxide crystals, metals and alloys, and studies the growth dynamics of space crystals; The research of "space environment forecasting and monitoring" can establish a space environment forecasting center, issue long-term, medium-term and short-term space environment forecasts and warnings, predict the effect, and ensure the safety of astronauts, manned spacecraft and space equipment.
Edit the implementation plan of this paragraph.
In the next few years, China's space technology development will implement a "three-step" plan.
Wang, director of the General Engineering Office of China Manned Space Engineering Office, revealed to reporters the "three-step" plan for the development of China's space technology in the next few years: "Shenzhou VII" spacecraft will be launched in 2008, with the task of realizing astronauts' spacewalk; From 2009 to 20 1 1 year, Shenzhou-8 spacecraft will take off with a more important mission and complete rendezvous and docking in space. The third step in the development of space technology is to build a space station.